Physical property improvement in nitrile resins by use of certain processing aids and fillers

ABSTRACT

Physical properties particularly including tensile modulus and heat-distortion temperature of high nitrile copolymer resins are improved by including therein a processing aid, such as tetra chloro phthalic anhydride, and a filler material, such as clay.

This invention relates to a mixture of a nitrile barrier resin and a combination of certain processing aids and fillers and to a process for preparing such mixtures to produce polymer compositions having improved physical properties.

Thermoplastic nitrile barrier resins, including those described in U.S. Pat. Nos. 3,426,102 and 3,586,737, are known to have many very desirable properties including gas barrier properties, impact resistance, chemical resistance, and the like. The present invention is an improvement over my co-pending U.S. patent application Ser. No. 870,053 filed Jan. 16, 1978, now U.S. Pat. No. 4,151,151, and other prior art in that it represents a composition comprising a blend of a prior art nitrile barrier resin with certain processing aids and fillers, which blend possesses unexpectedly higher heat-distortion temperature, high modulus, and in some cases improved fire retardancy.

The nitrile barrier resins useful in the present invention include those prepared by the polymerization of

(A) from 60 to 90% by weight of at least one nitrile having the structure ##STR1## wherein R is hydrogen, a lower alkyl group having from 1 to 4 carbon atoms, or a halogen,

(B) from 10 to 40% by weight based on the combined weight of (A) and (B) of at least one member selected from the group consisting of (1) an ester having the structure ##STR2## wherein R₁ is hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a halogen, and R₂ is an alkyl group having from 1 to 6 carbon atoms, (2) an alpha-olefin having the structure ##STR3## wherein R' and R" are alkyl groups having from 1 to 7 carbon atoms, (3) a vinyl ether selected from the group consisting of methyl vinyl ether, ethyl vinyl ether, the propyl vinyl ethers, and the butyl vinyl ethers, (4) vinyl acetate, (5) styrene, and (6) indene, in the presence of from 0 to 40 parts by weight of (C) a rubbery polymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and optionally a comonomer selected from the group consisting of styrene, a nitrile monomer having the structure ##STR4## wherein R has the foregoing designation, and an ester having the structure ##STR5## wherein R₁ and R₂ have the foregoing designations, said rubbery polymer containing from 50 to 100% by weight of polymerized conjugated diene and from 0 to 50% by weight of comonomer.

The nitrile barrier resins embodied in this invention can be prepared by any of the known general techniques of polymerization including the bulk polymerization, solution polymerization and emulsion or suspension polymerization techniques by batch, continuous or intermittent addition of monomers and other components. The preferred method is polymerization in aqueous emulsion or suspension.

The processing aids useful in this invention include at least one acid anhydride, dibasic acid, polybasic acid, amino acid, halogenated acid, halogenated acid anhydride, and more specific examples are glutaric anhydride; 1,2,4 benzene tricarboxylic anhydride; 1,2,4,5 benzene tetra carboxylic anhydride; maleic anhydride; mellitic anhydride, phthalic anhydride; succinic anhydride; tetra chloro phthalic anhydride; tetra bromo phthalic anhydride; dichloro maleic anhydride; adipic acid; azelaic acid; glutaric acid; maleic acid; malonic acid; pimelic acid; sebacic acid; suberic acid; succinic acid; dichloro phthalic acid; dichloro anthranilic acid; benzene tetra carboxylic acid; trimellitic acid; mellitic acid; citric acid; tartaric acid; anthranilic acid; glutamic acid; beta-hydroxy glutamic acid; lysine; tryptophane; phenylalanine; and others.

The fillers useful in this invention include at least one alumino silicate, alumina trihydrate, metal oxide, metal hydroxide, metal carbonate, metal sulfate, and others. More specific examples are calcium carbonate, magnesium carbonate, basic lead carbonate, zinc carbonate, aluminum hydroxide (hydrated), calcium hydroxide, lead hydroxide, zinc chromate, aluminum oxide, calcium oxide, chromium oxide, iron oxide, magnesium oxide, lead oxides, titanium dioxide, zinc oxide, aluminum silicate (hydrated), magnesium aluminum silicate, potassium aluminum silicate, sodium aluminum silicate, amorphous silica, calcium meta silicate, calcium silicate, diatomaceous silica, magnesium silicate, basic lead sulfate, barium sulfate, calcium sulfate, cadmium sulfide, mercuric sulfide, lead sulfide, and glass spheres. In addition, fibers including asbestos, glass, mineral and wollastonite may be used.

In the following examples which will further illustrate this invention, the amounts of the various ingredients are expressed in parts by weight unless otherwise indicated.

EXAMPLE 1

A. A rubber latex was prepared by polymerizing with continuous agitation at 45° C. in the substantial absence of molecular oxygen a mixture of the following ingredients:

    ______________________________________                                         Ingredient          Parts                                                      ______________________________________                                         acrylonitrile       30                                                         butadiene-1,3       70                                                         emulsifier (Gafac RE-610)*                                                                         2.4                                                        azobisisobutyronitrile                                                                             0.3                                                        t-dodecyl mercaptan 0.5                                                        water               200                                                        ______________________________________                                          *A mixture of R--0--(CH.sub.2 CH.sub.2 0-- ).sub.n PO.sub.3 M.sub.2 and        [R--0--(CH.sub.2 CH.sub.2 O--).sub.n ].sub.2 PO.sub.2 M wherein n is a         number from 1 to 40, R is an alkyl or aralkyl group and preferably a nony      phenyl group, and M is hydrogen, ammonia or an alkali metal, which             composition is sold by GAF Corporation.                                  

Before reaction was started, the pH of the mixture was adjusted to about 8 with KOH. The polymerization was carried out for 221/2 hours to a conversion of about 92% and a total solids of about 33.1%.

B. An impact-resistant gas-barrier resin was prepared by polymerization of a mixture of the following ingredients:

    ______________________________________                                         Ingredient              Parts                                                  ______________________________________                                         acrylonitrile           75                                                     methyl acrylate         25                                                     rubber solids in the form                                                      of latex A (above)      9                                                      potassium persulfate    0.06                                                   emulsifier (Gafac RE-610)                                                                              3                                                      modifier (n-dodecyl                                                            mercaptan)              1                                                      water                   200                                                    ______________________________________                                    

The pH was adjusted to about 7 with NaOH. The polymerization was carried out in the substantial absence of oxygen at 60° C. for 5 hours to produce a 91% conversion. The resulting latex was coagulated and the recovered resin was dried. The resin was compression molded in a 1/8-inch thick sheet mold at 320° F. and cooled. Samples cut from this sheet were tested and found to have an ASTM tensile modulus of 460,000 psi and an ASTM heat-distortion temperature at a 264 psi stress of 68° C.

EXAMPLE 2

The following formulation was employed:

    ______________________________________                                                            Parts                                                       ______________________________________                                         resin of Example 1   100                                                       tetra chloro phthalic anhydride                                                                     10                                                        hydrated clay        56                                                        ______________________________________                                    

This formulation was charged into an internal mixer heated to 235° C. and run for 5 minutes at a rotor speed of 35 rpm. The product was compression molded in a 1/8-inch thick sheet mold at 320° F. and cooled. Samples cut from the sheet produced were tested and found to have a tensile modulus of 1,000,000 psi and a heat-distortion temperature at a 264 psi stress of 73° C.

EXAMPLE 3

A formulation consisting of the following was weighed out:

    ______________________________________                                                            Parts                                                       ______________________________________                                         resin of Example 1   100                                                       tetra chloro phthalic anhydride                                                                      20                                                       magnesium oxide      111                                                       ______________________________________                                    

This formulation was charged into an internal mixer heated to 235° C. and run for 5 minutes at a rotor speed of 35 rpm. The product was then compression molded by charging into a 1/8-inch sheet mold held at 320° F. and cooled. Samples cut from the sheet were tested and found to have a tensile modulus of 1,850,000 psi and a heat-distortion temperature run at a 264 psi stress of 84° C.

EXAMPLE 4

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                                    Parts                                               ______________________________________                                         resin of Example 1           100                                               tetra chloro phthalic anhydride                                                                              10                                               barium sulfate               153                                               ______________________________________                                    

The resulting blend was found to have a tensile modulus of 780,000 psi and a heat-distortion temperature of 73° C.

EXAMPLE 5

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                                    Parts                                               ______________________________________                                         resin of Example 1           100                                               tetra chloro phthalic anhydride                                                                              10                                               calcium meta silicate        101                                               ______________________________________                                    

The resin blend was found to have a tensile modulus of 1,270,000 psi and a heat-distortion temperature of 75° C.

EXAMPLE 6

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                            Parts                                                       ______________________________________                                         resin of Example 1   100                                                       tetra chloro phthalic anhydride                                                                     17.3                                                      hydrous clay (alumino silicate)                                                                     266                                                       ______________________________________                                    

The blend was found to have a tensile modulus of 1,720,000 psi and a heat-distortion temperature of 80° C.

EXAMPLE 7

The procedure of Example 1 was used employing the following formulation:

    ______________________________________                                                                Parts                                                   ______________________________________                                         resin of Example 1       100                                                   tetra chloro phthalic anhydride                                                                         32.2                                                  hydrous clay             254                                                   ______________________________________                                    

The blend was found to have a tensile modulus of 1,690,000 psi and a heat-distortion temperature of 80° C.

EXAMPLE 8

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                            Parts                                                       ______________________________________                                         resin of Example 1   100                                                       tetra chloro phthalic anhydride                                                                     26.1                                                      hydrous clay         336                                                       ______________________________________                                    

The resulting blend was found to have a tensile modulus of 3,160,000 psi and a heat-distortion temperature of 88° C.

EXAMPLE 9

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                               Parts                                                    ______________________________________                                         resin of Example 1      100                                                    phthalic anhydride      10                                                     magnesium oxide         56                                                     ______________________________________                                    

The resulting blend was found to have a tensile modulus of 1,700,000 psi and a heat-distortion temperature of 80° C.

EXAMPLE 10

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                           Parts                                                        ______________________________________                                         resin of Example 1  100                                                        1,2,4 benzene tricarboxylic                                                                        17.4                                                       anhydride                                                                      magnesium oxide     57                                                         ______________________________________                                    

The resulting blend was found to have a tensile modulus of 1,220,000 psi and a heat-distortion temperature of 82° C.

EXAMPLE 11

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                               Parts                                                    ______________________________________                                         resin of Example 1      100                                                    1,2,4,5 benzene tetra   17.4                                                   carboxylic anhydride                                                           magnesium oxide         57                                                     ______________________________________                                    

The resulting blend was found to have a tensile modulus of 1,090,000 psi and a heat-distortion temperature of 80° C.

EXAMPLE 12

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                            Parts                                                       ______________________________________                                         resin of Example 1   100                                                       tetra chloro phthalic anhydride                                                                     8.6                                                       magnesium oxide      56                                                        ______________________________________                                    

The resulting blend was found to have a tensile modulus of 1,000,000 psi and a heat-distortion temperature of 79° C.

EXAMPLE 13

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                                Parts                                                   ______________________________________                                         resin of Example 1       100                                                   tetra bromo phthalic anhydride                                                                          43.6                                                  hydrous clay             226                                                   ______________________________________                                    

The resulting blend was found to have a tensile modulus of 2,580,000 psi and a heat-distortion temperature of 83° C.

EXAMPLE 14

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                                Parts                                                   ______________________________________                                         resin of Example 1       100                                                   tetra chloro phthalic anhydride                                                                         4.3                                                   hydrated alumina         10.5                                                  ______________________________________                                    

The final blend was found to have a tensile modulus of 497,000 psi and a heat-distortion temperature of 69° C.

EXAMPLE 15

The procedure of Example 3 was used employing the following formulation:

    ______________________________________                                                                Parts                                                   ______________________________________                                         resin of Example 1       100                                                   tetra chloro phthalic anhydride                                                                         4.3                                                   calcium carbonate        11.7                                                  ______________________________________                                    

The resulting blend was found to have a tensile modulus of 5,160,000 psi and a heat-distortion temperature of 69° C. 

I claim:
 1. The composition comprising a blend of a resin, from 2 to 50 parts by weight per hundred parts by weight of resin of an polycarboxylic acid anhydride processing aid, and from 5 to 400 parts by weight per 100 parts by weight of resin of a filler selected from the group consisting of calcium carbonate, magnesium carbonate, basic lead carbonate, zinc carbonate, aluminum hydroxide (hydrated), calcium hydroxide, lead hydroxide, zinc chromate, aluminum oxide, calcium oxide, chromium oxide, iron oxide, magnesium oxide, lead oxides, titanium dioxide, zinc oxide, aluminum silicate (hydrated), magnesium aluminum silicate, potassium aluminum silicate, sodium aluminum silicate, amorphous silica, calcium meta silicate, calcium silicate, diatomaceous silica, magnesium silicate, basic lead sulfate, barium sulfate, calcium sulfate, cadmium sulfide, mercuric sulfide and lead sulfide said resin being a polymer which results from the polymerization of(A) from 60 to 90% by weight of at least one nitrile having the structure ##STR6## wherein R is hydrogen, a lower alkyl group having from 1 to 4 carbon atoms, or a halogen, (B) from 10 to 40% by weight based on the combined weight of (A) and (B) of an ester having the structure ##STR7## wherein R₁ is hydrogen, an alkyl group having from 1 to 4 carbon atoms, or a halogen, and R₂ is an alkyl group having from 1 to 6 carbon atoms,in the presence of from 1 to 40 parts by weight of (C) a rubbery polymer of a conjugated diene monomer selected from the group consisting of butadiene and isoprene and optionally a comonomer selected from the group consisting of styrene, a nitrile monomer having the structure ##STR8## wherein R has the foregoing designation, and an ester having the structure ##STR9## wherein R₁ and R₂ have the foregoing designations, said rubbery polymer containing from 50 to 100% by weight of polymerized conjugated diene and from 0 to 50% by weight of comonomer.
 2. The composition of claim 1 wherein the processing aid is at least one member selected from the group consisting of glutaric anhydride; 1,2,4 benzene tricarboxylic anhydride; 1,2,4,5 benzene tetra carboxylic anhydride; maleic anhydride; mellitic anhydride; phthalic anhydride; succinic anhydride; tetra chloro phthalic anhydride; tetra bromo phthalic anhydride; and dichloro maleic anhydride.
 3. The composition of claim 1 wherein the processing aid is tetra chloro phthalic anhydride and the filler is hydrated clay.
 4. The composition of claim 1 wherein the processing aid is tetra chloro phthalic anhydride and the filler is magnesium oxide.
 5. The composition of claim 1 wherein the processing aid is tetra chloro phthalic anhydride and the filler is barium sulfate.
 6. The composition of claim 1 wherein the processing aid is tetra chloro phthalic anhydride and the filler is calcium meta silicate.
 7. The composition of claim 1 wherein the processing aid is phthalic anhydride and the filler is magnesium oxide.
 8. The composition of claim 1 wherein the processing aid is 1,2,4 benzene tricarboxylic anhydride and the filler is magnesium oxide.
 9. The composition of claim 1 wherein the processing aid is tetra bromo phthalic anhydride and the filler is hydrous clay.
 10. The composition of claim 1 wherein 10.5 to 336 parts by weight of the filler is present in the blend.
 11. The composition of claim 10 wherein more than 56 parts by weight of the filler is present in the blend.
 12. The composition of claim 1 wherein (B) is methyl acrylate. 